This invention relates to a local distribution utility center for a raised floor, and method of providing communications services to a workgroup. The invention is especially applicable to communications wiring for servicing data and telecommunications equipment of a centralized office workgroup. Such equipment typically includes a telephone, FAX machine, modem or central computer connection, printer connection, and/or local area network. The workgroup may include any number of persons with common needs and interests, and who are located in relatively close proximity to each other in an office. For example, the workgroup may include 8 to 12 workstations assigned to work collectively on a particular project.
Since the location and equipment needs of the workgroup are generally temporary and often changing, there has developed a need in the industry for a wiring system which will readily accommodate the addition of workstations to the workgroup, added equipment, relocation, and other changes. In the past, accommodating such changes meant abandoning old wiring, rewiring with new wiring, clogged and unusable wiring pathways, and a considerable amount of labor and cost. Moreover, since each manufacturer's office equipment typically had its own proprietary wiring scheme, switching from one manufacturer to another generally required a complete rewiring of all affected workstations.
In response to these concerns and other developments in the industry, the concept of "structured wiring" emerged. Basically, structured wiring means that the wiring of every workstation follows a fixed plan. The three basic characteristics of structured wiring include:
(1) It is application-independent.
(2) Every workstation is wired the same.
(3) All workstations are star-wired to a central distribution point, such as a main wiring closet.
An "application-independent" wiring system enables the wiring system to handle all communication services and equipment that the office worker may need over the life of the wiring. In theory, re-wiring should never be needed in a structured system, since the wiring is already in place to accommodate any service combination. Workers are thereby free to move workstations throughout the work place without extensive labor and cost.
Star-wiring the workstations enables quick and efficient relocation and other workstation changes, since all service switching can be done at one distribution point (or at the most, several distribution points if the changes encompass several star-wired zones). Star-wiring also makes it easier to access and troubleshoot the wiring of a data network from one central location. Moreover, new services can be easily added and connected into the system. Most new network equipment has already been designed to drop into a star-wired topology.
Because of standardization of wiring in the industry and the acceptance of wiring standardization by communications equipment manufacturers, structured wiring has developed into a convenient and workable system. Standardization began with the 1991 release of the EIA/TIA 568 "Commercial Building Telecommunications Wiring Standard". In addition to standardizing the types and specifications of wiring components, the EIA/TIA Standard set guidelines around which most of today's structured wiring systems have been designed. The Standard describes a simple horizontal system that connects to the network backbone wiring or data equipment in a wiring closet, and consists of individual cable runs from the closet to each workstation outlet port. FIG. 7 shows how this conventional system would apply to a typical cluster of eight offices.
Problems With Conventional Structured Wiring
While the EIA/TIA Standard and the structured wiring concept go a long way toward solving many of the wiring problems of the past, much of the industry has interpreted the Standard too rigidly and failed to recognize the full potential of this system. One of the more common misunderstandings is that the Standard requires "dedicated" cable runs from the wiring closet to each workstation outlet port for each communications service.
Although dedicated wiring may be sufficient for a single telephone and a single data service per workstation, in today's office environment, workers generally require many additional services. For example, a modern workstation may be wired for telephone, FAX, modem or central computer connection, printer connection, and a local area network. The typical workstation needs anywhere from three to six service connections per desk.
With dedicated wiring, every workstation is wired with individual cable runs from the wiring closet to the workstation for each of the desired services. An extremely large number of cable runs are thus required to accommodate one or more workgroups in a given area. As shown in FIG. 7, each line represents a bundle of three to six cables. In order to distribute the cables about the floor of the office, considerable space must be available in cable trays, conduits, or pathways that lead from the wiring closet to the workstations. In an existing building, this space is generally not available.
Terminating all of these cable runs into one small wiring closet can also be a problem. All of the cables must be terminated to distribution panels that patch over to other distributions panels. In order to realize the advantages of a star-wired configuration, the mounting of panels and the routing of patch cables must allow easy access for troubleshooting and the administration of future moves or additions. A growing conglomeration of network concentrators, file servers, controllers, and other communications equipment must also be mounted somewhere in the room, again with access for maintenance. The heat build-up from the equipment must somehow be dissipated.
Again, this requires space which probably does not exist in a previously wired building. Even in a new building, unless it was designed with the foresight and commitment to dedicate valuable floor space to a relatively large and spacious wiring closet, chances are that the closet is still inadequate, or will soon become inadequate.
In addition, long cable runs and crowded wiring closets can limit the capability of the wiring to handle high speed data. Network equipment designers continually fight the battle between signal loss and noise build-up. Long cable runs attenuate the signals and hamper the ability of the receiving equipment to correctly interpret the signal from background noise. Moreover, commonly used unshielded cabling is more vulnerable to noise than shielded cabling. Crowded wiring closets add to the problem, since the build-up of electrical fields radiating from closely-packed wiring and equipment can also cause interferences.
Thus, in an open office environment where workstations are intentionally non-permanent, the problems of how to effectively interface long, fixed cable runs with movable workstations, and how to avoid extensive wiring rerouting or waste when the workstations are moved must be addressed and resolved.
The Local Distribution Alternative
The present invention addresses the above problems of standard wiring, and serves the needs of a modern workgroup through the concept of local distribution. The invention is applicable in combination with a raised floor, such as that disclosed in the Applicant's pending patent application, U.S. Ser. No. 8/161,977, now U.S. Pat. No. 5,440,841.
According to the invention, all of the panels and equipment associated with a workgroup are condensed into a single local distribution utility center located on the floor near the workgroup. FIG. 8 shows the same office cluster illustrated in FIG. 7, but wired using local distribution.
The invention frees up considerable space in the wiring closet, and drastically shortens the cable runs to the workstations, thereby gaining valuable performance margin for high speed applications. The invention reduces the amount and cost of the workstation cabling, and adds flexibility to the workgroup to locally administer moves or changes. Moreover, with short interconnections between workstations and distribution center, moving workstations is made easier with minimum disruption and cable rerouting. The workgroup can readily track down local network problems, and isolate itself from other network problems if necessary.